Adolescents who get 6 hours of sleep or less may face health and behavior issues, particularly those who get 5 hours of sleep per night on a regular basis, says Ryan C. Meldrum in a recently published study in Preventive Medicine.

“Studies typically examine the implications of getting anything less than eight hours of sleep at night. What I wanted to investigate was whether there might be differences in the consequences of sleep deprivation depending on the severity of such deprivations,” says Meldrum, researcher and criminal justice professor at Florida International University (FIU). “In other words, I wanted to know if getting six or seven hours of sleep at night really places teens at risk for problematic health and behavior outcomes, or whether the impact of sleep deprivation is confined to teens at the extreme who average less than six hours of sleep at night.”

In the study for which more than 12,000 teens were surveyed, Meldrum links extreme sleep deprivation to 12 outcomes ranging from obesity, substance use, drunk driving, and even suicidal tendencies. For example:

Teenagers who say they get an average of five hours of sleep per night are 37% more likely to report engaging in fighting than those who get an average of eight or more hours of sleep. That percentage jumps to 137% for those who get less than five hours of sleep on average.

Teenagers who get five hours of sleep per night are 40% more likely to be obese than those who get eight or more hours of sleep, and that percentage jumps to 83% for those who get less than five hours of sleep.

Yet, for these and many other outcomes analyzed in the study, Meldrum found that getting six or seven hours of sleep at night did not place teens at any greater risk for health and behavioral problems than those who get eight or more hours of sleep at night.

“What this means is that, at least for the outcomes investigated in this study, minor deprivations in sleep do not appear to be all that harmful during adolescence,” Meldrum says. “Rather, it is the much smaller portion of the teenage population that experiences more severe deprivations in sleep that parents, teachers, and practitioners need to be on the lookout for. Efforts to assist these teens in achieving just one more hour of sleep at night could significantly reduce their risk of poor health and bad behavior.”